Transdermal and transmucosal powdered drug delivery

High-velocity powder injection is a promising new drug-delivery technique t hat provides needle- and pain-free delivery of traditional drugs, drugs fro m biotechnology such as proteins, peptides, and oligonucleotides as well as traditional and genetic vaccines. The energy of a transient helium gas jet accelerates fine drug particles of 20 mu m-100 mu m diameter to high veloc ities and delivers them into skin or mucosal sites. This review describes t he configuration and operating principles of devices that accelerate the pa rticles, the required properties of the particles, the characteristics of t he target tissues, and features of the developmental test methods. Preclini cal and clinical results that best characterize the technology and introduc e its potential as a drug-delivery platform are presented.